Poker Chip Quantites and Colors Needed for a Game

How many Poker Chip Colors do I need?
 
You only need three or four different poker chip colors. The ratio of colors needed for a no-limit poker tournament should be something like 4/3/2/1, meaning that you should buy (4) chips of your lowest denomination, (3) chips of your next denomination, (2) chips of your next denomination, and (1) chip of your highest denomination.

If you are purchasing (1,000) poker chips - you should buy

(400) chips of your lowest denomination ($1)
(300) chips of your next denomination ($5)
(200) chips of your next denomination ($25)
(100) chips of your next denomination ($100)

If you are purchasing (500) chips - you should buy 200/150/100/50 chips.
 
You need more of the lower-denomination chips than higher-denomination chips. Your tournament will begin with a large number of players, each making small bets because of the low blinds at the start of a tournament. You will need lots of lower-denomination chips to accommodate the large number of players making all these small bets. As your tournament progresses, players will drop out and the blinds (and bets) will increase in value. The middle stages of your tournament will consist of a medium number of players making medium-sized bets. The end of your tournament will consist of a few players making high-sized bets. This means that overall, you will should own numerous low-valued chips, less medium-valued chips, and only a few high-valued chips. Keep in mind that you will also require some additional high-denomination chips to issue rebuys and perform chip color-ups.
 
The 4/3/2/1/ chip distribution ratio is not "standard" but is a good starting point for setting up your poker chip set. The important thing is to match your set to the buyin and blinds that you plan to use for your tournaments. If you only want three poker chips colors - a 4/3/2 ratio is fine, but adding a fourth color will help with color-ups and rebuys. A 2/2/1 split might be acceptable, especially if you play a lot of cash games.